US20130214046A1 - Reader antenna and rfid electronic shelf including the same - Google Patents
Reader antenna and rfid electronic shelf including the same Download PDFInfo
- Publication number
- US20130214046A1 US20130214046A1 US13/746,657 US201313746657A US2013214046A1 US 20130214046 A1 US20130214046 A1 US 20130214046A1 US 201313746657 A US201313746657 A US 201313746657A US 2013214046 A1 US2013214046 A1 US 2013214046A1
- Authority
- US
- United States
- Prior art keywords
- antenna
- horizontal
- vertical
- feed line
- dielectric layer
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q9/00—Electrically-short antennas having dimensions not more than twice the operating wavelength and consisting of conductive active radiating elements
- H01Q9/04—Resonant antennas
- H01Q9/06—Details
- H01Q9/065—Microstrip dipole antennas
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
- G06K7/00—Methods or arrangements for sensing record carriers, e.g. for reading patterns
- G06K7/10—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation
- G06K7/10009—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation sensing by radiation using wavelengths larger than 0.1 mm, e.g. radio-waves or microwaves
- G06K7/10316—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation sensing by radiation using wavelengths larger than 0.1 mm, e.g. radio-waves or microwaves using at least one antenna particularly designed for interrogating the wireless record carriers
- G06K7/10346—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation sensing by radiation using wavelengths larger than 0.1 mm, e.g. radio-waves or microwaves using at least one antenna particularly designed for interrogating the wireless record carriers the antenna being of the far field type, e.g. HF types or dipoles
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q9/00—Electrically-short antennas having dimensions not more than twice the operating wavelength and consisting of conductive active radiating elements
- H01Q9/04—Resonant antennas
- H01Q9/44—Resonant antennas with a plurality of divergent straight elements, e.g. V-dipole, X-antenna; with a plurality of elements having mutually inclined substantially straight portions
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q1/00—Details of, or arrangements associated with, antennas
- H01Q1/12—Supports; Mounting means
- H01Q1/22—Supports; Mounting means by structural association with other equipment or articles
- H01Q1/2208—Supports; Mounting means by structural association with other equipment or articles associated with components used in interrogation type services, i.e. in systems for information exchange between an interrogator/reader and a tag/transponder, e.g. in Radio Frequency Identification [RFID] systems
- H01Q1/2216—Supports; Mounting means by structural association with other equipment or articles associated with components used in interrogation type services, i.e. in systems for information exchange between an interrogator/reader and a tag/transponder, e.g. in Radio Frequency Identification [RFID] systems used in interrogator/reader equipment
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q21/00—Antenna arrays or systems
- H01Q21/06—Arrays of individually energised antenna units similarly polarised and spaced apart
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q21/00—Antenna arrays or systems
- H01Q21/24—Combinations of antenna units polarised in different directions for transmitting or receiving circularly and elliptically polarised waves or waves linearly polarised in any direction
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q21/00—Antenna arrays or systems
- H01Q21/28—Combinations of substantially independent non-interacting antenna units or systems
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q9/00—Electrically-short antennas having dimensions not more than twice the operating wavelength and consisting of conductive active radiating elements
- H01Q9/04—Resonant antennas
- H01Q9/0407—Substantially flat resonant element parallel to ground plane, e.g. patch antenna
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q9/00—Electrically-short antennas having dimensions not more than twice the operating wavelength and consisting of conductive active radiating elements
- H01Q9/04—Resonant antennas
- H01Q9/16—Resonant antennas with feed intermediate between the extremities of the antenna, e.g. centre-fed dipole
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q9/00—Electrically-short antennas having dimensions not more than twice the operating wavelength and consisting of conductive active radiating elements
- H01Q9/04—Resonant antennas
- H01Q9/16—Resonant antennas with feed intermediate between the extremities of the antenna, e.g. centre-fed dipole
- H01Q9/28—Conical, cylindrical, cage, strip, gauze, or like elements having an extended radiating surface; Elements comprising two conical surfaces having collinear axes and adjacent apices and fed by two-conductor transmission lines
- H01Q9/285—Planar dipole
Definitions
- the present invention relates to a reader antenna and an RFID electronic shelf including the same, and more particularly, to a reader antenna capable of simultaneously recognizing many individual items (item level tagging), and an RFID electronic shelf including the same.
- RFID radio frequency identification
- UHF ultra-high frequency
- the material and shape of items to be mounted on an RFID electronic shelf, the shape of a packaging material, the method of displaying items, and so on may be diversified according to application fields.
- a reader antenna for an RFID electronic shelf is emerging as one of the methods for simultaneously recognizing a plurality of items displayed on the RFID electronic shelf.
- the RFID technology of the HF band employing magnetic coupling is being studied in the RFID electronic shelf field, placing stress on excellent field characteristics for liquids and metals compared to the UHF band, but the recognition rate is drastically degraded due to interference between RFID tags, interference between tags and readers, and the like.
- the UHF band RFID technology using backscattering of electromagnetic waves having advantages in that it has a relatively long recognition distance and similar field characteristics to those in the UHF band in a near field zone, is being studied in the RFID electronic shelf field.
- the reader antenna for the RFID electronic shelf has to be easily mounted on the electronic shelf, and has to be capable of transmission and reception of polarization of arbitrary tags. Further, a technique of forming a near field on the RFID electronic shelf is required to avoid tag misrecognition caused by a fading zone.
- a reader antenna for an RFID electronic shelf having the above-mentioned characteristics by the conventional HF band antenna technology and the UHF band antenna technology.
- the present invention has been made in an effort to provide a reader antenna which is easy to install because of its ultrathin profile and that offers an improved recognition rate, and an RFID electronic shelf including the same.
- An exemplary embodiment of the present invention provides a reader antenna including dipole antennas, the dipole antennas including: a horizontal dipole antenna having the characteristic of horizontal polarization; and a dipole antenna perpendicular to the horizontal dipole antenna and including a vertical dipole antenna having the characteristic of vertical polarization, wherein the horizontal dipole antenna and the vertical dipole antenna may both have the characteristic of circular polarization.
- the horizontal dipole antenna may include: a dielectric layer; a first horizontal unipole antenna formed in a first direction on the top surface of the dielectric layer; and a second horizontal unipole antenna formed on the bottom surface of the dielectric layer and coupled to the first horizontal unipole antenna to form the dipole antennas.
- the horizontal dipole antenna may further include: a first horizontal feed line formed on the top surface of the dielectric layer and connected to the first horizontal unipole antenna; and a second horizontal feed line formed on the bottom surface of the dielectric layer and connected to the second horizontal unipole antenna, wherein a first horizontal impedance matching slot may be formed at a connecting portion of the first horizontal unipole antenna connected to the first horizontal feed line, and a second horizontal impedance matching slot may be formed at a connecting portion of the second horizontal unipole antenna connected to the second horizontal feed line.
- the first horizontal unipole antenna may be symmetrical to the second horizontal unipole antenna with respect to the first horizontal feed line.
- the vertical dipole antenna may include: the dielectric layer; a first vertical unipole antenna formed in a second direction perpendicular to the first direction on the top surface of the dielectric layer; and a second vertical unipole antenna formed in the second direction on the bottom surface of the dielectric layer and coupled to the first vertical unipole antenna to form the dipole antennas.
- the vertical dipole antenna may further include: a first vertical feed line formed on the top surface of the dielectric layer and connected to the first vertical unipole antenna; and a second vertical feed line formed on the bottom surface of the dielectric layer and connected to the second vertical unipole antenna, wherein a first vertical impedance matching slot may be formed at a connecting portion of the first vertical unipole antenna connected to the first vertical feed line, and a second vertical impedance matching slot may be formed at a connecting portion of the second vertical unipole antenna connected to the second vertical feed line.
- the first vertical unipole antenna may be symmetrical to the second vertical unipole antenna with respect to the first vertical feed line.
- the first horizontal impedance matching slot, the second horizontal impedance matching slot, the first vertical impedance matching slot, and the second vertical impedance matching slot may each have a horizontal slot portion and a vertical slot portion, and impedance matching may be performed by adjusting the lengths of the horizontal and vertical slot portions.
- a reader antenna including a patch antenna, the patch antenna including: a dielectric layer; and a polygonal antenna formed on the top surface of the dielectric layer and having the characteristic of circular polarization.
- the patch antenna may further include a patch feed line formed on the top surface of the dielectric layer and connected to the polygonal antenna, wherein the patch feed line may be spaced a predetermined length apart from the central axis of the polygonal axis.
- the patch feed line may be inserted a predetermined length into the polygonal antenna.
- an RFID electronic shelf including a reader antenna
- the RFID electronic shelf including: a shelf portion including a horizontal shelf for displaying items and a vertical shelf perpendicular to the horizontal shelf; and the reader antenna including a plurality of patch antennas and a plurality of dipole antennas formed on the horizontal shelf and the vertical shelf, respectively.
- the RFID electronic shelf may further include a phase shifter block connected to the plurality of patch antennas and forming a time-varying near field.
- Each of the patch antennas may include: a dielectric layer; and a polygonal antenna formed on the top surface of the dielectric layer and having the characteristic of circular polarization.
- Each of the patch antennas may further include a patch feed line formed on the top surface of the dielectric layer and connected to the polygonal antenna, wherein the patch feed line may be spaced a predetermined length apart from the central axis of the polygonal axis.
- the patch feed line may be inserted a predetermined length into the polygonal antenna.
- the RFID electronic shelf may further include a bent impedance transformer connected to the patch feed line.
- the RFID electronic shelf may further include a patch current phase delay unit connected to the patch feed line.
- the plurality of patch antennas may include four patch antennas of two rows and two columns connected to the patch feed line and gathering to form a unit patch antenna, and the patch feed line of the unit patch antenna may be connected to a unit feed port.
- the phase shifter block may be connected to the unit feed port.
- the dipole antennas may include: a horizontal dipole antenna having the characteristic of horizontal polarization; and a dipole antenna perpendicular to the horizontal dipole antenna and including a vertical dipole antenna having the characteristic of vertical polarization, wherein the horizontal dipole antenna and the vertical dipole antenna may both have the characteristic of circular polarization.
- the horizontal dipole antenna may include: a dielectric layer; a first horizontal unipole antenna formed in a first direction on the top surface of the dielectric layer; and a second horizontal unipole antenna formed on the bottom surface of the dielectric layer and coupled to the first horizontal unipole antenna to form the dipole antennas.
- the horizontal dipole antenna may further include: a first horizontal feed line formed on the top surface of the dielectric layer and connected to the first horizontal unipole antenna; and a second horizontal feed line formed on the bottom surface of the dielectric layer and connected to the second horizontal unipole antenna, wherein a first horizontal impedance matching slot may be formed at a connecting portion of the first horizontal unipole antenna connected to the first horizontal feed line, and a second horizontal impedance matching slot may be formed at a connecting portion of the second horizontal unipole antenna connected to the second horizontal feed line.
- the first horizontal unipole antenna may be symmetrical to the second horizontal unipole antenna with respect to the first horizontal feed line.
- the vertical dipole antenna may include: the dielectric layer; a first vertical unipole antenna formed in a second direction perpendicular to the first direction on the top surface of the dielectric layer; and a second vertical unipole antenna formed in the second direction on the bottom surface of the dielectric layer and coupled to the first vertical unipole antenna to form the dipole antennas.
- the vertical dipole antenna may further include: a first vertical feed line formed on the top surface of the dielectric layer and connected to the first vertical unipole antenna; and a second vertical feed line formed on the bottom surface of the dielectric layer and connected to the second vertical unipole antenna, wherein a first vertical impedance matching slot may be formed at a connecting portion of the first vertical unipole antenna connected to the first vertical feed line, and a second vertical impedance matching slot may be formed at a connecting portion of the second vertical unipole antenna connected to the second vertical feed line.
- the first vertical unipole antenna may be symmetrical to the second vertical unipole antenna with respect to the first vertical feed line.
- the first horizontal impedance matching slot, the second horizontal impedance matching slot, the first vertical impedance matching slot, and the second vertical impedance matching slot each may have a horizontal slot portion and a vertical slot portion, and impedance matching may be performed by adjusting the lengths of the horizontal and vertical slot portions.
- the reader antenna according to an exemplary embodiment of the present invention can be easily stored in an electronic shelf because it is realized in an ultrathin structure using a single-layered dielectric substrate.
- the RFID electronic shelf according to an exemplary embodiment of the present invention can stably recognize items, even if a plurality of items are displayed in an arbitrary form on the electronic shelf, by arranging a reader antenna on the electronic shelf according to the mounting position of the antenna and the display form of items.
- the RFID electronic shelf according to an exemplary embodiment of the present invention can offer an improved recognition rate because a fading zone can be eliminated from an electronic shelf by forming a time-varying near field on the electronic shelf by the use of both an antenna and a phase shifter block.
- FIG. 1 is a top plan view of a reader antenna according to a first exemplary embodiment of the present invention.
- FIG. 2 is a perspective view of a horizontal dipole antenna of the reader antenna according to the first exemplary embodiment of the present invention.
- FIG. 3 is a cross-sectional view taken along line III-III of FIG. 2 .
- FIG. 4 is a top plan view of a first horizontal unipole antenna and a first vertical unipole antenna formed on the top surface of a dielectric layer of the reader antenna according to the first exemplary embodiment of the present invention.
- FIG. 5 is a top plan view of a second horizontal unipole antenna and a second vertical unipole antenna formed on the bottom surface of the dielectric layer of the reader antenna according to the first exemplary embodiment of the present invention.
- FIG. 6 is a perspective view of a reader antenna according to a second exemplary embodiment of the present invention.
- FIG. 7 is a perspective view of a unit patch antenna having reader antennas arranged in two rows and two columns according to the second exemplary embodiment of the present invention.
- FIG. 8 is a perspective view of an RFID electronic shelf including the reader antenna according to the first exemplary embodiment and the reader antenna according to the second exemplary embodiment.
- FIG. 1 is a top plan view of a reader antenna according to a first exemplary embodiment of the present invention
- FIG. 2 is a perspective view of a horizontal dipole antenna of the reader antenna according to the first exemplary embodiment of the present invention
- FIG. 3 is a cross-sectional view taken along line III-III of FIG. 2
- FIG. 4 is a top plan view of a first horizontal unipole antenna and a first vertical unipole antenna formed on the top surface of a dielectric layer of the reader antenna according to the first exemplary embodiment of the present invention
- FIG. 5 is a top plan view of a second horizontal unipole antenna and a second vertical unipole antenna formed on the bottom surface of the dielectric layer of the reader antenna according to the first exemplary embodiment of the present invention.
- the reader antenna according to the first exemplary embodiment of the present invention includes dipole antennas 3 , the dipole antennas 3 including a horizontal dipole antenna 1 having the characteristic of horizontal polarization and a vertical dipole antenna 2 perpendicular to the horizontal dipole antenna 1 and having the characteristic of vertical polarization.
- the horizontal dipole antenna 1 and the vertical dipole antenna 2 both have the characteristic of circular polarization.
- the horizontal dipole antenna 1 includes a single dielectric layer 100 , a radiation-type first horizontal unipole antenna 10 formed in a first direction, i.e., the horizontal direction, on the top surface of the dielectric layer 100 , and a radiation-type second horizontal unipole antenna 20 formed on the bottom surface of the dielectric layer 100 and coupled to the first horizontal unipole antenna 10 to form the dipole antennas.
- a first horizontal feed line 50 connected to the first horizontal unipole antenna 10 and supplying current to the first horizontal unipole antenna 10 is formed on the top surface of the dielectric layer 100
- a second horizontal feed line 60 connected to the second horizontal unipole antenna 20 and supplying current to the second horizontal unipole antenna 20 is formed on the bottom surface of the dielectric layer 100 .
- the first horizontal unipole antenna 10 and the second horizontal unipole antenna 20 can be easily arranged.
- the first horizontal unipole antenna 10 is symmetrical to the second horizontal unipole antenna 20 with respect to the first horizontal feed line 50 .
- a first horizontal impedance matching slot 15 for impedance matching between the first horizontal feed line 50 and the first horizontal unipole antenna 10 is formed at a connecting portion of the first horizontal unipole antenna 10 connected to the first horizontal feed line 50
- a second horizontal impedance matching slot 25 for impedance matching between the second horizontal feed line 60 and the second horizontal unipole antenna 20 is formed at a connecting portion of the second horizontal unipole antenna 20 connected to the second horizontal feed line 60 .
- the first horizontal impedance matching slot 15 and the second horizontal impedance matching slot 25 are T-shaped slots, each having a vertical slot portion 15 b and 25 b connected to an intermediate portion of a horizontal slot portion 15 a and 25 a . Impedance matching can be made easy by adjusting the length d 1 of the horizontal slot portion and the length d 2 of the vertical slot portion.
- the vertical dipole antenna 2 may include the dielectric layer 100 , a first vertical unipole antenna 30 formed in a second direction perpendicular to the first direction, i.e., the vertical direction, on the top surface of the dielectric layer 100 , and a second vertical unipole antenna 40 formed in the second direction on the bottom surface of the dielectric layer 100 and coupled to the first vertical unipole antenna 30 to form the dipole antennas.
- a first vertical feed line 70 connected to the first vertical unipole antenna 30 is formed on the top surface of the dielectric layer 100
- a second vertical feed line 80 connected to the second vertical unipole antenna 40 is formed on the bottom surface of the dielectric layer 100 .
- a first vertical impedance matching slot 35 for impedance matching between the first vertical feed line 70 and the first vertical unipole antenna 30 is formed at a connecting portion of the first vertical unipole antenna 30 connected to the first vertical feed line 70
- a second vertical impedance matching slot 45 is formed at a connecting portion of the second vertical unipole antenna 40 connected to the second vertical feed line 80 .
- the first vertical unipole antenna 30 is symmetrical to the second vertical unipole antenna 40 with respect to the first vertical feed line 70 .
- the first horizontal impedance matching slot 15 , the second horizontal impedance matching slot 25 , the first vertical impedance matching slot 35 , and the second vertical impedance matching slot 45 each have a horizontal slot portion and a vertical slot portion, and impedance matching can be performed by adjusting the lengths d 1 and d 2 of the horizontal and vertical slot portions.
- the first horizontal unipole antenna 10 and first vertical unipole antenna 30 shown in FIG. 4 and the second horizontal unipole antenna 20 and second vertical unipole antenna 30 shown in FIG. 5 can be used to exhibit the characteristic of circular polarization.
- the first horizontal unipole antenna 10 and the first vertical unipole antenna 30 are formed on the top surface of the dielectric layer 100 .
- the first horizontal impedance matching slot 15 and the first vertical impedance matching slot 35 are formed in the first horizontal unipole antenna 10 and the first vertical unipole antenna 30 , respectively, to achieve impedance matching.
- the first horizontal unipole antenna 10 is horizontally formed to transmit and receive horizontal polarization
- the first vertical unipole antenna 30 is vertically formed to transmit and receive vertical polarization.
- the first horizontal feed line 50 feeds electric power to the first horizontal unipole antenna 10
- the first vertical feed line 70 feeds electric power to the first vertical unipole antenna 30 .
- the first horizontal feed line 50 and the first vertical feed line 70 are divided from the first feed line 80 .
- a dipole current phase delay unit 71 is formed on the first vertical feed line 70 so that the phase of the current fed to the first vertical unipole antenna 30 is delayed by 90 degrees relative to the phase of the current fed to the first horizontal unipole antenna 1 .
- the second horizontal unipole antenna 20 and the second vertical unipole antenna 40 are formed on the bottom surface of the dielectric layer 100 .
- the second horizontal impedance matching slot 25 and the second vertical impedance matching slot 45 are formed in the second horizontal unipole antenna 20 and the second vertical unipole antenna 40 , respectively, to achieve impedance matching.
- the second horizontal unipole antenna 20 is horizontally formed to transmit and receive horizontal polarization
- the second vertical unipole antenna 40 is vertically formed to transmit and receive vertical polarization.
- the second horizontal feed line 20 feeds electric power to the second horizontal unipole antenna 60
- the second vertical feed line 80 feeds electric power to the second vertical unipole antenna 40 .
- the second horizontal feed line 60 and the second vertical feed line 80 are divided from a second feed line 90 .
- a tapered ground 81 is formed by tapering the second horizontal feed line 60 and the second vertical feed line 80 at a junction between them, so that current is divided into two exact halves and fed to the second horizontal unipole antenna 20 and the second vertical unipole antenna 40 , respectively.
- the first horizontal unipole antenna 10 and the first vertical unipole antenna 30 are formed on the top surface of the dielectric layer 100
- the second horizontal unipole antenna 20 and the second vertical unipole antenna 40 are formed on the bottom surface of the dielectric layer 100 , thereby forming a dipole antenna 3 having the characteristic of circular polarization.
- the reader antenna is a dipole antenna in the first exemplary embodiment
- the reader antenna may be a patch antenna in a second exemplary embodiment.
- FIGS. 6 and 7 a reader antenna according to the second exemplary embodiment of the present invention will be described in detail.
- FIG. 6 is a perspective view of a reader antenna according to a second exemplary embodiment of the present invention.
- the reader antenna according to the second exemplary embodiment of the present invention is a patch antenna 4 including a dielectric layer 100 and a radiation-type polygonal antenna 200 formed on the top surface of the dielectric layer 100 and having the characteristic of circular polarization.
- the polygon antenna 200 is an antenna which is symmetrical with respect to a symmetrical axis C.
- a patch feed line 400 connected to the polygonal antenna 200 and supplying current to the polygonal antenna 200 is formed on the top surface of the dielectric layer 100 .
- the patch feed line 400 uses an offset feeding method so as to be spaced a predetermined length P 1 apart from the central axis C of the polygonal antenna 2 , thereby achieving the characteristic of circular polarization.
- the patch feed line 400 uses an inset feeding method so as to be inserted a predetermined length P 2 into the polygonal antenna 200 , thereby efficiently achieving impedance matching in various ways.
- FIG. 7 is a perspective view of a unit patch antenna having reader antennas arranged in two rows and two columns according to the second exemplary embodiment of the present invention.
- a plurality of patch antennas 4 i.e., four patch antennas of two rows and two columns connected to the patch feed line 400 , gather to form a unit patch antenna 210 .
- the unit patch antenna 210 includes a pair of first unit patch antennas 211 and 212 and a pair of second unit patch antennas 213 and 214 facing each other with respect to the central axis A of the arrangement.
- a patch current phase delay unit 430 is formed at the patch feed line 400 to improve the impedance bandwidth of the unit patch antenna 210 and the axial ratio of circular polarization.
- FIG. 8 is a perspective view of an RFID electronic shelf including the reader antenna according to the first exemplary embodiment and the reader antenna according to the second exemplary embodiment.
- the RFID electronic shelf includes a shelf portion 1000 including a horizontal shelf 1100 for displaying items and a vertical shelf 1200 perpendicular to the horizontal shelf 1100 , and a reader antenna 2000 formed on the shelf portion 1000 .
- the reader antenna 2000 includes a plurality of patch antennas 4 formed on the horizontal shelf 1100 and a plurality of dipole antennas 3 formed on the vertical shelf 1200 .
- the RFID electronic shelf may be scaled up or down according to its structure.
- the two dipole antennas 3 are formed on the vertical shelf 1200 behind a plurality of items to be stored and delayed, the items can be stably recognized.
- a plurality of items displayed in a single layer can be stably recognized because the three unit patch antennas 210 are formed on the horizontal shelf 1100 , spaced apart from each other.
- a phase shifter block 3000 connected to a plurality of patch antennas may be installed to form a time-varying near field. That is, a time-varying near field can be formed by installing a phase shifter block 3000 connected to three unit patch antennas 210 . The time-varying near field can eliminate a fading zone that may be formed on the RFID electronic shelf. At this point, the phase shifter block 3000 is able to cause a current having a sequential phase difference that varies with time to be fed to unit feed ports 410 of the three unit patch antennas 210 , respectively.
- dipole antenna 4 patch antenna 10: first horizontal unipole antenna 20: second horizontal unipole antenna 30: first vertical unipole antenna 40: second vertical unipole antenna 100: dielectric layer 200: polygonal antenna 210: unit patch antenna 400: temperature sensor 1000: shelf portion 2000: reader antenna 3000: phase shifter block
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Toxicology (AREA)
- General Health & Medical Sciences (AREA)
- Electromagnetism (AREA)
- Computer Networks & Wireless Communication (AREA)
- Artificial Intelligence (AREA)
- Computer Vision & Pattern Recognition (AREA)
- General Physics & Mathematics (AREA)
- Theoretical Computer Science (AREA)
- Variable-Direction Aerials And Aerial Arrays (AREA)
- Details Of Aerials (AREA)
Abstract
Description
- This application claims priority to and the benefit of Korean Patent Application No. 10-2012-0016593 filed in the Korean Intellectual Property Office on Feb. 17, 2012, the entire contents of which are incorporated herein by reference.
- (a) Field of the Invention
- The present invention relates to a reader antenna and an RFID electronic shelf including the same, and more particularly, to a reader antenna capable of simultaneously recognizing many individual items (item level tagging), and an RFID electronic shelf including the same.
- (b) Description of the Related Art
- The application field of radio frequency identification (RFID) in the ultra-high frequency (UHF) band has been extending from case or box unit recognition to individual item recognition as it has been recently used for an RFID electronic shelf.
- The material and shape of items to be mounted on an RFID electronic shelf, the shape of a packaging material, the method of displaying items, and so on may be diversified according to application fields. Thus, a reader antenna for an RFID electronic shelf is emerging as one of the methods for simultaneously recognizing a plurality of items displayed on the RFID electronic shelf.
- Recently, active research has been conducted on RFID electronic shelf applications in the field of RFID technology in the high frequency (HF) band and the field of RFID technology in the ultra-high frequency (UHF) band. The RFID technology of the HF band employing magnetic coupling is being studied in the RFID electronic shelf field, placing stress on excellent field characteristics for liquids and metals compared to the UHF band, but the recognition rate is drastically degraded due to interference between RFID tags, interference between tags and readers, and the like. The UHF band RFID technology using backscattering of electromagnetic waves, having advantages in that it has a relatively long recognition distance and similar field characteristics to those in the UHF band in a near field zone, is being studied in the RFID electronic shelf field. However, there is still a problem of recognition rate degradation due to a fading zone, caused by a change made to items to be displayed and a display method, and a polarization mismatch caused by the direction of tags to be displayed. Particularly, a conventional fixed reader antenna is directly applied to an electronic shelf in most cases because little research has been conducted regarding a reader antenna for an RFID electronic shelf in the UHF band. This leads to poor mountability of the reader antenna on the shelf.
- Moreover, some reader antennas being studied for RFID electronic shelf applications in the UHF band cannot solve the problem of misrecognition caused by a polarization mismatch with tags, and a fading zone.
- That is, in order to simultaneously recognize a plurality of tags in an item display environment where a plurality of items having different physical properties and shapes may be arbitrarily displayed on an RFID electronic shelf, the reader antenna for the RFID electronic shelf has to be easily mounted on the electronic shelf, and has to be capable of transmission and reception of polarization of arbitrary tags. Further, a technique of forming a near field on the RFID electronic shelf is required to avoid tag misrecognition caused by a fading zone. However, there are many difficulties in designing a reader antenna for an RFID electronic shelf having the above-mentioned characteristics by the conventional HF band antenna technology and the UHF band antenna technology.
- The present invention has been made in an effort to provide a reader antenna which is easy to install because of its ultrathin profile and that offers an improved recognition rate, and an RFID electronic shelf including the same.
- An exemplary embodiment of the present invention provides a reader antenna including dipole antennas, the dipole antennas including: a horizontal dipole antenna having the characteristic of horizontal polarization; and a dipole antenna perpendicular to the horizontal dipole antenna and including a vertical dipole antenna having the characteristic of vertical polarization, wherein the horizontal dipole antenna and the vertical dipole antenna may both have the characteristic of circular polarization.
- The horizontal dipole antenna may include: a dielectric layer; a first horizontal unipole antenna formed in a first direction on the top surface of the dielectric layer; and a second horizontal unipole antenna formed on the bottom surface of the dielectric layer and coupled to the first horizontal unipole antenna to form the dipole antennas.
- The horizontal dipole antenna may further include: a first horizontal feed line formed on the top surface of the dielectric layer and connected to the first horizontal unipole antenna; and a second horizontal feed line formed on the bottom surface of the dielectric layer and connected to the second horizontal unipole antenna, wherein a first horizontal impedance matching slot may be formed at a connecting portion of the first horizontal unipole antenna connected to the first horizontal feed line, and a second horizontal impedance matching slot may be formed at a connecting portion of the second horizontal unipole antenna connected to the second horizontal feed line.
- The first horizontal unipole antenna may be symmetrical to the second horizontal unipole antenna with respect to the first horizontal feed line.
- The vertical dipole antenna may include: the dielectric layer; a first vertical unipole antenna formed in a second direction perpendicular to the first direction on the top surface of the dielectric layer; and a second vertical unipole antenna formed in the second direction on the bottom surface of the dielectric layer and coupled to the first vertical unipole antenna to form the dipole antennas.
- The vertical dipole antenna may further include: a first vertical feed line formed on the top surface of the dielectric layer and connected to the first vertical unipole antenna; and a second vertical feed line formed on the bottom surface of the dielectric layer and connected to the second vertical unipole antenna, wherein a first vertical impedance matching slot may be formed at a connecting portion of the first vertical unipole antenna connected to the first vertical feed line, and a second vertical impedance matching slot may be formed at a connecting portion of the second vertical unipole antenna connected to the second vertical feed line.
- The first vertical unipole antenna may be symmetrical to the second vertical unipole antenna with respect to the first vertical feed line.
- The first horizontal impedance matching slot, the second horizontal impedance matching slot, the first vertical impedance matching slot, and the second vertical impedance matching slot may each have a horizontal slot portion and a vertical slot portion, and impedance matching may be performed by adjusting the lengths of the horizontal and vertical slot portions.
- Another embodiment of the present invention provides a reader antenna including a patch antenna, the patch antenna including: a dielectric layer; and a polygonal antenna formed on the top surface of the dielectric layer and having the characteristic of circular polarization.
- The patch antenna may further include a patch feed line formed on the top surface of the dielectric layer and connected to the polygonal antenna, wherein the patch feed line may be spaced a predetermined length apart from the central axis of the polygonal axis.
- The patch feed line may be inserted a predetermined length into the polygonal antenna.
- Yet another embodiment of the present invention provides an RFID electronic shelf including a reader antenna, the RFID electronic shelf including: a shelf portion including a horizontal shelf for displaying items and a vertical shelf perpendicular to the horizontal shelf; and the reader antenna including a plurality of patch antennas and a plurality of dipole antennas formed on the horizontal shelf and the vertical shelf, respectively.
- The RFID electronic shelf may further include a phase shifter block connected to the plurality of patch antennas and forming a time-varying near field.
- Each of the patch antennas may include: a dielectric layer; and a polygonal antenna formed on the top surface of the dielectric layer and having the characteristic of circular polarization.
- Each of the patch antennas may further include a patch feed line formed on the top surface of the dielectric layer and connected to the polygonal antenna, wherein the patch feed line may be spaced a predetermined length apart from the central axis of the polygonal axis.
- The patch feed line may be inserted a predetermined length into the polygonal antenna.
- The RFID electronic shelf may further include a bent impedance transformer connected to the patch feed line.
- The RFID electronic shelf may further include a patch current phase delay unit connected to the patch feed line.
- The plurality of patch antennas may include four patch antennas of two rows and two columns connected to the patch feed line and gathering to form a unit patch antenna, and the patch feed line of the unit patch antenna may be connected to a unit feed port.
- The phase shifter block may be connected to the unit feed port.
- The dipole antennas may include: a horizontal dipole antenna having the characteristic of horizontal polarization; and a dipole antenna perpendicular to the horizontal dipole antenna and including a vertical dipole antenna having the characteristic of vertical polarization, wherein the horizontal dipole antenna and the vertical dipole antenna may both have the characteristic of circular polarization.
- The horizontal dipole antenna may include: a dielectric layer; a first horizontal unipole antenna formed in a first direction on the top surface of the dielectric layer; and a second horizontal unipole antenna formed on the bottom surface of the dielectric layer and coupled to the first horizontal unipole antenna to form the dipole antennas.
- The horizontal dipole antenna may further include: a first horizontal feed line formed on the top surface of the dielectric layer and connected to the first horizontal unipole antenna; and a second horizontal feed line formed on the bottom surface of the dielectric layer and connected to the second horizontal unipole antenna, wherein a first horizontal impedance matching slot may be formed at a connecting portion of the first horizontal unipole antenna connected to the first horizontal feed line, and a second horizontal impedance matching slot may be formed at a connecting portion of the second horizontal unipole antenna connected to the second horizontal feed line.
- The first horizontal unipole antenna may be symmetrical to the second horizontal unipole antenna with respect to the first horizontal feed line.
- The vertical dipole antenna may include: the dielectric layer; a first vertical unipole antenna formed in a second direction perpendicular to the first direction on the top surface of the dielectric layer; and a second vertical unipole antenna formed in the second direction on the bottom surface of the dielectric layer and coupled to the first vertical unipole antenna to form the dipole antennas.
- The vertical dipole antenna may further include: a first vertical feed line formed on the top surface of the dielectric layer and connected to the first vertical unipole antenna; and a second vertical feed line formed on the bottom surface of the dielectric layer and connected to the second vertical unipole antenna, wherein a first vertical impedance matching slot may be formed at a connecting portion of the first vertical unipole antenna connected to the first vertical feed line, and a second vertical impedance matching slot may be formed at a connecting portion of the second vertical unipole antenna connected to the second vertical feed line.
- The first vertical unipole antenna may be symmetrical to the second vertical unipole antenna with respect to the first vertical feed line.
- The first horizontal impedance matching slot, the second horizontal impedance matching slot, the first vertical impedance matching slot, and the second vertical impedance matching slot each may have a horizontal slot portion and a vertical slot portion, and impedance matching may be performed by adjusting the lengths of the horizontal and vertical slot portions.
- The reader antenna according to an exemplary embodiment of the present invention can be easily stored in an electronic shelf because it is realized in an ultrathin structure using a single-layered dielectric substrate.
- The RFID electronic shelf according to an exemplary embodiment of the present invention can stably recognize items, even if a plurality of items are displayed in an arbitrary form on the electronic shelf, by arranging a reader antenna on the electronic shelf according to the mounting position of the antenna and the display form of items.
- The RFID electronic shelf according to an exemplary embodiment of the present invention can offer an improved recognition rate because a fading zone can be eliminated from an electronic shelf by forming a time-varying near field on the electronic shelf by the use of both an antenna and a phase shifter block.
-
FIG. 1 is a top plan view of a reader antenna according to a first exemplary embodiment of the present invention. -
FIG. 2 is a perspective view of a horizontal dipole antenna of the reader antenna according to the first exemplary embodiment of the present invention. -
FIG. 3 is a cross-sectional view taken along line III-III ofFIG. 2 . -
FIG. 4 is a top plan view of a first horizontal unipole antenna and a first vertical unipole antenna formed on the top surface of a dielectric layer of the reader antenna according to the first exemplary embodiment of the present invention. -
FIG. 5 is a top plan view of a second horizontal unipole antenna and a second vertical unipole antenna formed on the bottom surface of the dielectric layer of the reader antenna according to the first exemplary embodiment of the present invention. -
FIG. 6 is a perspective view of a reader antenna according to a second exemplary embodiment of the present invention. -
FIG. 7 is a perspective view of a unit patch antenna having reader antennas arranged in two rows and two columns according to the second exemplary embodiment of the present invention. -
FIG. 8 is a perspective view of an RFID electronic shelf including the reader antenna according to the first exemplary embodiment and the reader antenna according to the second exemplary embodiment. - The present invention will be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments of the invention are shown. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the principles for the present invention.
- In order to clarify the present invention, elements extrinsic to the description are omitted from the details of this description, and like reference numerals refer to like elements throughout the specification.
- Now, a reader antenna according to a first exemplary embodiment of the present invention will be described in detail with reference to
FIGS. 1 to 5 . -
FIG. 1 is a top plan view of a reader antenna according to a first exemplary embodiment of the present invention,FIG. 2 is a perspective view of a horizontal dipole antenna of the reader antenna according to the first exemplary embodiment of the present invention,FIG. 3 is a cross-sectional view taken along line III-III ofFIG. 2 ,FIG. 4 is a top plan view of a first horizontal unipole antenna and a first vertical unipole antenna formed on the top surface of a dielectric layer of the reader antenna according to the first exemplary embodiment of the present invention, andFIG. 5 is a top plan view of a second horizontal unipole antenna and a second vertical unipole antenna formed on the bottom surface of the dielectric layer of the reader antenna according to the first exemplary embodiment of the present invention. - As shown in
FIG. 1 , the reader antenna according to the first exemplary embodiment of the present invention includesdipole antennas 3, thedipole antennas 3 including ahorizontal dipole antenna 1 having the characteristic of horizontal polarization and avertical dipole antenna 2 perpendicular to thehorizontal dipole antenna 1 and having the characteristic of vertical polarization. - The
horizontal dipole antenna 1 and thevertical dipole antenna 2 both have the characteristic of circular polarization. - As shown in
FIG. 2 andFIG. 3 , thehorizontal dipole antenna 1 includes asingle dielectric layer 100, a radiation-type firsthorizontal unipole antenna 10 formed in a first direction, i.e., the horizontal direction, on the top surface of thedielectric layer 100, and a radiation-type secondhorizontal unipole antenna 20 formed on the bottom surface of thedielectric layer 100 and coupled to the firsthorizontal unipole antenna 10 to form the dipole antennas. - A first
horizontal feed line 50 connected to the firsthorizontal unipole antenna 10 and supplying current to the firsthorizontal unipole antenna 10 is formed on the top surface of thedielectric layer 100, and a secondhorizontal feed line 60 connected to the secondhorizontal unipole antenna 20 and supplying current to the secondhorizontal unipole antenna 20 is formed on the bottom surface of thedielectric layer 100. Using the firsthorizontal feed line 50 and the secondhorizontal feed line 60, the firsthorizontal unipole antenna 10 and the secondhorizontal unipole antenna 20 can be easily arranged. The firsthorizontal unipole antenna 10 is symmetrical to the secondhorizontal unipole antenna 20 with respect to the firsthorizontal feed line 50. - A first horizontal
impedance matching slot 15 for impedance matching between the firsthorizontal feed line 50 and the firsthorizontal unipole antenna 10 is formed at a connecting portion of the firsthorizontal unipole antenna 10 connected to the firsthorizontal feed line 50, and a second horizontalimpedance matching slot 25 for impedance matching between the secondhorizontal feed line 60 and the secondhorizontal unipole antenna 20 is formed at a connecting portion of the secondhorizontal unipole antenna 20 connected to the secondhorizontal feed line 60. - The first horizontal
impedance matching slot 15 and the second horizontalimpedance matching slot 25 are T-shaped slots, each having avertical slot portion horizontal slot portion - Like the
horizontal dipole antenna 1, thevertical dipole antenna 2 may include thedielectric layer 100, a firstvertical unipole antenna 30 formed in a second direction perpendicular to the first direction, i.e., the vertical direction, on the top surface of thedielectric layer 100, and a secondvertical unipole antenna 40 formed in the second direction on the bottom surface of thedielectric layer 100 and coupled to the firstvertical unipole antenna 30 to form the dipole antennas. - A first
vertical feed line 70 connected to the firstvertical unipole antenna 30 is formed on the top surface of thedielectric layer 100, and a secondvertical feed line 80 connected to the secondvertical unipole antenna 40 is formed on the bottom surface of thedielectric layer 100. - A first vertical
impedance matching slot 35 for impedance matching between the firstvertical feed line 70 and the firstvertical unipole antenna 30 is formed at a connecting portion of the firstvertical unipole antenna 30 connected to the firstvertical feed line 70, and a second verticalimpedance matching slot 45 is formed at a connecting portion of the secondvertical unipole antenna 40 connected to the secondvertical feed line 80. - The first
vertical unipole antenna 30 is symmetrical to the secondvertical unipole antenna 40 with respect to the firstvertical feed line 70. - The first horizontal
impedance matching slot 15, the second horizontalimpedance matching slot 25, the first verticalimpedance matching slot 35, and the second verticalimpedance matching slot 45 each have a horizontal slot portion and a vertical slot portion, and impedance matching can be performed by adjusting the lengths d1 and d2 of the horizontal and vertical slot portions. - The configuration of the horizontal dipole antenna and the vertical dipole antenna will be concretely described below.
- The first
horizontal unipole antenna 10 and firstvertical unipole antenna 30 shown inFIG. 4 and the secondhorizontal unipole antenna 20 and secondvertical unipole antenna 30 shown inFIG. 5 can be used to exhibit the characteristic of circular polarization. - As shown in
FIG. 4 , the firsthorizontal unipole antenna 10 and the firstvertical unipole antenna 30 are formed on the top surface of thedielectric layer 100. The first horizontalimpedance matching slot 15 and the first verticalimpedance matching slot 35 are formed in the firsthorizontal unipole antenna 10 and the firstvertical unipole antenna 30, respectively, to achieve impedance matching. - The first
horizontal unipole antenna 10 is horizontally formed to transmit and receive horizontal polarization, and the firstvertical unipole antenna 30 is vertically formed to transmit and receive vertical polarization. The firsthorizontal feed line 50 feeds electric power to the firsthorizontal unipole antenna 10, and the firstvertical feed line 70 feeds electric power to the firstvertical unipole antenna 30. The firsthorizontal feed line 50 and the firstvertical feed line 70 are divided from thefirst feed line 80. - A dipole current
phase delay unit 71 is formed on the firstvertical feed line 70 so that the phase of the current fed to the firstvertical unipole antenna 30 is delayed by 90 degrees relative to the phase of the current fed to the firsthorizontal unipole antenna 1. - With the phase difference of 90 degrees between the currents respectively fed to the first
vertical unipole antenna 30 and the firsthorizontal unipole antenna 10, circular polarization is radiated through the firstvertical unipole antenna 30 and the firsthorizontal unipole antenna 10. - As shown in
FIG. 5 , the secondhorizontal unipole antenna 20 and the secondvertical unipole antenna 40 are formed on the bottom surface of thedielectric layer 100. The second horizontalimpedance matching slot 25 and the second verticalimpedance matching slot 45 are formed in the secondhorizontal unipole antenna 20 and the secondvertical unipole antenna 40, respectively, to achieve impedance matching. - The second
horizontal unipole antenna 20 is horizontally formed to transmit and receive horizontal polarization, and the secondvertical unipole antenna 40 is vertically formed to transmit and receive vertical polarization. The secondhorizontal feed line 20 feeds electric power to the secondhorizontal unipole antenna 60, and the secondvertical feed line 80 feeds electric power to the secondvertical unipole antenna 40. The secondhorizontal feed line 60 and the secondvertical feed line 80 are divided from asecond feed line 90. - A
tapered ground 81 is formed by tapering the secondhorizontal feed line 60 and the secondvertical feed line 80 at a junction between them, so that current is divided into two exact halves and fed to the secondhorizontal unipole antenna 20 and the secondvertical unipole antenna 40, respectively. - As shown in
FIG. 1 , the firsthorizontal unipole antenna 10 and the firstvertical unipole antenna 30 are formed on the top surface of thedielectric layer 100, and the secondhorizontal unipole antenna 20 and the secondvertical unipole antenna 40 are formed on the bottom surface of thedielectric layer 100, thereby forming adipole antenna 3 having the characteristic of circular polarization. - Although the reader antenna is a dipole antenna in the first exemplary embodiment, the reader antenna may be a patch antenna in a second exemplary embodiment.
- Hereinafter, referring to
FIGS. 6 and 7 , a reader antenna according to the second exemplary embodiment of the present invention will be described in detail. -
FIG. 6 is a perspective view of a reader antenna according to a second exemplary embodiment of the present invention. - As shown in
FIG. 6 , the reader antenna according to the second exemplary embodiment of the present invention is apatch antenna 4 including adielectric layer 100 and a radiation-type polygonal antenna 200 formed on the top surface of thedielectric layer 100 and having the characteristic of circular polarization. - The
polygon antenna 200 is an antenna which is symmetrical with respect to a symmetrical axis C. - A
patch feed line 400 connected to thepolygonal antenna 200 and supplying current to thepolygonal antenna 200 is formed on the top surface of thedielectric layer 100. - The
patch feed line 400 uses an offset feeding method so as to be spaced a predetermined length P1 apart from the central axis C of thepolygonal antenna 2, thereby achieving the characteristic of circular polarization. - Alternatively, the
patch feed line 400 uses an inset feeding method so as to be inserted a predetermined length P2 into thepolygonal antenna 200, thereby efficiently achieving impedance matching in various ways. -
FIG. 7 is a perspective view of a unit patch antenna having reader antennas arranged in two rows and two columns according to the second exemplary embodiment of the present invention. - As shown in
FIG. 7 , a plurality ofpatch antennas 4, i.e., four patch antennas of two rows and two columns connected to thepatch feed line 400, gather to form aunit patch antenna 210. - The
unit patch antenna 210 includes a pair of firstunit patch antennas unit patch antennas - Current fed from a
unit feed port 410 is divided into halves and fed, and the impedance of the divided current is transformed by abent impedance transformer 420 and fed to the pair of firstunit patch antennas unit patch antennas - Moreover, a patch current
phase delay unit 430 is formed at thepatch feed line 400 to improve the impedance bandwidth of theunit patch antenna 210 and the axial ratio of circular polarization. - Hereinafter, an RFID electronic shelf including the reader antenna according to the first exemplary embodiment and the reader antenna according to the second exemplary embodiment will be described in detail.
-
FIG. 8 is a perspective view of an RFID electronic shelf including the reader antenna according to the first exemplary embodiment and the reader antenna according to the second exemplary embodiment. - As shown in
FIG. 8 , the RFID electronic shelf includes ashelf portion 1000 including ahorizontal shelf 1100 for displaying items and avertical shelf 1200 perpendicular to thehorizontal shelf 1100, and areader antenna 2000 formed on theshelf portion 1000. - The
reader antenna 2000 includes a plurality ofpatch antennas 4 formed on thehorizontal shelf 1100 and a plurality ofdipole antennas 3 formed on thevertical shelf 1200. - Although the present exemplary embodiment has been described with respect to, but is not limited to, three
unit patch antennas 210 spaced apart from each other and twodipole antennas 3 being symmetrical with respect to afeeding point 5, the RFID electronic shelf may be scaled up or down according to its structure. - Since the two
dipole antennas 3 are formed on thevertical shelf 1200 behind a plurality of items to be stored and delayed, the items can be stably recognized. - Moreover, a plurality of items displayed in a single layer can be stably recognized because the three
unit patch antennas 210 are formed on thehorizontal shelf 1100, spaced apart from each other. - Meanwhile, a
phase shifter block 3000 connected to a plurality of patch antennas may be installed to form a time-varying near field. That is, a time-varying near field can be formed by installing aphase shifter block 3000 connected to threeunit patch antennas 210. The time-varying near field can eliminate a fading zone that may be formed on the RFID electronic shelf. At this point, thephase shifter block 3000 is able to cause a current having a sequential phase difference that varies with time to be fed to unit feedports 410 of the threeunit patch antennas 210, respectively. - While the present invention has been shown and described in connection with the exemplary embodiments, it will be apparent to those skilled in the art that modifications and variations can be made without departing from the spirit and scope of the invention as defined by the appended claims.
-
<Description of Symbols> 3: dipole antenna 4: patch antenna 10: first horizontal unipole antenna 20: second horizontal unipole antenna 30: first vertical unipole antenna 40: second vertical unipole antenna 100: dielectric layer 200: polygonal antenna 210: unit patch antenna 400: temperature sensor 1000: shelf portion 2000: reader antenna 3000: phase shifter block
Claims (28)
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
KR10-2012-0016593 | 2012-02-17 | ||
KR1020120016593A KR20130095128A (en) | 2012-02-17 | 2012-02-17 | Reader antenna and rfid electric shelf including the same |
Publications (2)
Publication Number | Publication Date |
---|---|
US20130214046A1 true US20130214046A1 (en) | 2013-08-22 |
US9033233B2 US9033233B2 (en) | 2015-05-19 |
Family
ID=48981525
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US13/746,657 Expired - Fee Related US9033233B2 (en) | 2012-02-17 | 2013-01-22 | Reader antenna and RFID electronic shelf including the same |
Country Status (2)
Country | Link |
---|---|
US (1) | US9033233B2 (en) |
KR (1) | KR20130095128A (en) |
Cited By (19)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN103682595A (en) * | 2013-11-29 | 2014-03-26 | 北京邮电大学 | Ultra-wide band circularly polarized reader-writer antenna |
US20160066137A1 (en) * | 2014-09-03 | 2016-03-03 | CloudLeaf, Inc. | Systems, methods and devices for asset status determination |
CN105609943A (en) * | 2015-12-23 | 2016-05-25 | 中国电子科技集团公司第五十研究所 | Novel butterfly-shaped dipole antenna |
CN106207495A (en) * | 2016-08-23 | 2016-12-07 | 江苏省东方世纪网络信息有限公司 | Dual polarized antenna and radiating element thereof |
US9641964B2 (en) | 2014-09-03 | 2017-05-02 | CloudLeaf, Inc. | Systems, methods and devices for asset status determination |
USD788082S1 (en) * | 2015-09-20 | 2017-05-30 | Airgain Incorporated | Antenna |
EP3236278A1 (en) * | 2016-04-20 | 2017-10-25 | Rohde & Schwarz GmbH & Co. KG | Directional antenna module |
CN107437648A (en) * | 2016-05-28 | 2017-12-05 | 富泰华工业(深圳)有限公司 | More feed-in ultra-high frequency RFID label antennas |
EP3256801A4 (en) * | 2015-02-11 | 2018-10-10 | Promega Corporation | Radio frequency identification techniques in an ultra-low temperature environment |
CN110233327A (en) * | 2019-05-28 | 2019-09-13 | 北京星网锐捷网络技术有限公司 | A kind of UHF RFID reader antenna and switching method |
JP2020503218A (en) * | 2016-12-21 | 2020-01-30 | テトラ ラバル ホールディングス アンド ファイナンス エス エイ | Reel holder |
US10681490B2 (en) | 2014-09-03 | 2020-06-09 | CloudLeaf, Inc. | Events based asset location and management system |
WO2020130459A1 (en) * | 2018-12-21 | 2020-06-25 | Samsung Electronics Co., Ltd. | Antenna module and electronic device comprising thereof |
CN111864368A (en) * | 2020-07-27 | 2020-10-30 | 安徽大学 | Low-profile broadband circularly polarized antenna for 5G communication and design method thereof |
US10942251B2 (en) | 2014-09-03 | 2021-03-09 | CloudLeaf, Inc. | Asset location and management system with distributed processing |
WO2021058479A1 (en) * | 2019-09-26 | 2021-04-01 | Assa Abloy Ab | Ultra-wide band antenna configuration for physical access control system |
EP3688840A4 (en) * | 2017-09-30 | 2021-09-01 | Intel Corporation | Perpendicular end fire antennas |
US11436544B2 (en) | 2014-09-03 | 2022-09-06 | CloudLeaf, Inc. | System for managing an industrial workflow |
US20230114757A1 (en) * | 2021-10-12 | 2023-04-13 | Qualcomm Incorporated | Multi-directional dual-polarized antenna system |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN107611596B (en) * | 2017-07-24 | 2019-09-24 | 西北工业大学 | A kind of broad band vertical depolarized dipole antenna of VHF frequency range of compact installation |
KR101954819B1 (en) * | 2018-04-04 | 2019-03-07 | 서울대학교산학협력단 | A 1d tightly coupled dipole array antenna |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6823177B1 (en) * | 1996-03-28 | 2004-11-23 | Nortel Matra Cellular | Radio station with circularly polarised antennas |
US7161537B2 (en) * | 2004-04-27 | 2007-01-09 | Intelwaves Technologies Ltd. | Low profile hybrid phased array antenna system configuration and element |
Family Cites Families (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
KR100964117B1 (en) | 2008-06-05 | 2010-06-16 | 엘에스산전 주식회사 | Antenna system and rfid terminal using the same |
CN102089928A (en) | 2008-07-07 | 2011-06-08 | 传感电子有限责任公司 | Switchable patch antenna for RFID shelf reader system |
KR100995716B1 (en) | 2008-08-04 | 2010-11-19 | 한국전자통신연구원 | Near-field radio frequency identification reader antenna |
US20110090130A1 (en) | 2009-10-15 | 2011-04-21 | Electronics And Telecommunications Research Institute | Rfid reader antenna and rfid shelf having the same |
KR101317183B1 (en) | 2009-10-15 | 2013-10-15 | 한국전자통신연구원 | RFID Reader Antenna and RFID Shelf including the same |
KR101056504B1 (en) | 2009-10-30 | 2011-08-12 | 주식회사 루셈 | WHF Passive RFID Label Tag with Equilateral Radiation Pattern |
JP2011219240A (en) | 2010-04-12 | 2011-11-04 | Cresco-Id Co Ltd | Planar antenna-equipped shelf device |
-
2012
- 2012-02-17 KR KR1020120016593A patent/KR20130095128A/en not_active Application Discontinuation
-
2013
- 2013-01-22 US US13/746,657 patent/US9033233B2/en not_active Expired - Fee Related
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6823177B1 (en) * | 1996-03-28 | 2004-11-23 | Nortel Matra Cellular | Radio station with circularly polarised antennas |
US7161537B2 (en) * | 2004-04-27 | 2007-01-09 | Intelwaves Technologies Ltd. | Low profile hybrid phased array antenna system configuration and element |
Cited By (27)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN103682595A (en) * | 2013-11-29 | 2014-03-26 | 北京邮电大学 | Ultra-wide band circularly polarized reader-writer antenna |
US10681490B2 (en) | 2014-09-03 | 2020-06-09 | CloudLeaf, Inc. | Events based asset location and management system |
US20160066137A1 (en) * | 2014-09-03 | 2016-03-03 | CloudLeaf, Inc. | Systems, methods and devices for asset status determination |
US11436544B2 (en) | 2014-09-03 | 2022-09-06 | CloudLeaf, Inc. | System for managing an industrial workflow |
US9641964B2 (en) | 2014-09-03 | 2017-05-02 | CloudLeaf, Inc. | Systems, methods and devices for asset status determination |
US10942251B2 (en) | 2014-09-03 | 2021-03-09 | CloudLeaf, Inc. | Asset location and management system with distributed processing |
US9860688B2 (en) * | 2014-09-03 | 2018-01-02 | CloudLeaf, Inc. | Systems, methods and devices for asset status determination |
US10057723B2 (en) | 2014-09-03 | 2018-08-21 | CloudLeaf, Inc. | Systems, methods and devices for asset status determination |
EP3256801A4 (en) * | 2015-02-11 | 2018-10-10 | Promega Corporation | Radio frequency identification techniques in an ultra-low temperature environment |
USD788082S1 (en) * | 2015-09-20 | 2017-05-30 | Airgain Incorporated | Antenna |
CN105609943A (en) * | 2015-12-23 | 2016-05-25 | 中国电子科技集团公司第五十研究所 | Novel butterfly-shaped dipole antenna |
EP3236278A1 (en) * | 2016-04-20 | 2017-10-25 | Rohde & Schwarz GmbH & Co. KG | Directional antenna module |
US10790584B2 (en) | 2016-04-20 | 2020-09-29 | Rohde & Schwarz Gmbh & Co. Kg | Directional antenna module and method |
CN107437648A (en) * | 2016-05-28 | 2017-12-05 | 富泰华工业(深圳)有限公司 | More feed-in ultra-high frequency RFID label antennas |
CN106207495B (en) * | 2016-08-23 | 2020-12-04 | 江苏省东方世纪网络信息有限公司 | Dual-polarized antenna and radiating element thereof |
CN106207495A (en) * | 2016-08-23 | 2016-12-07 | 江苏省东方世纪网络信息有限公司 | Dual polarized antenna and radiating element thereof |
JP7199356B2 (en) | 2016-12-21 | 2023-01-05 | テトラ ラバル ホールディングス アンド ファイナンス エス エイ | reel holder |
JP2020503218A (en) * | 2016-12-21 | 2020-01-30 | テトラ ラバル ホールディングス アンド ファイナンス エス エイ | Reel holder |
EP3688840A4 (en) * | 2017-09-30 | 2021-09-01 | Intel Corporation | Perpendicular end fire antennas |
US11362424B2 (en) | 2018-12-21 | 2022-06-14 | Samsung Electronics Co., Ltd. | Antenna module and electronic device comprising thereof |
WO2020130459A1 (en) * | 2018-12-21 | 2020-06-25 | Samsung Electronics Co., Ltd. | Antenna module and electronic device comprising thereof |
CN110233327A (en) * | 2019-05-28 | 2019-09-13 | 北京星网锐捷网络技术有限公司 | A kind of UHF RFID reader antenna and switching method |
WO2021058479A1 (en) * | 2019-09-26 | 2021-04-01 | Assa Abloy Ab | Ultra-wide band antenna configuration for physical access control system |
US11955723B2 (en) | 2019-09-26 | 2024-04-09 | Assa Abloy Ab | Ultra-wide band antenna configuration for physical access control system |
CN111864368A (en) * | 2020-07-27 | 2020-10-30 | 安徽大学 | Low-profile broadband circularly polarized antenna for 5G communication and design method thereof |
US20230114757A1 (en) * | 2021-10-12 | 2023-04-13 | Qualcomm Incorporated | Multi-directional dual-polarized antenna system |
US11784418B2 (en) * | 2021-10-12 | 2023-10-10 | Qualcomm Incorporated | Multi-directional dual-polarized antenna system |
Also Published As
Publication number | Publication date |
---|---|
KR20130095128A (en) | 2013-08-27 |
US9033233B2 (en) | 2015-05-19 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US9033233B2 (en) | Reader antenna and RFID electronic shelf including the same | |
KR100995716B1 (en) | Near-field radio frequency identification reader antenna | |
US7525487B2 (en) | RFID shelf antennas | |
CN101504998B (en) | Radio frequency identification antenna and apparatus for managing items using the same | |
US20110227710A1 (en) | Rfid tag, rfid tag set and rfid system | |
KR101317183B1 (en) | RFID Reader Antenna and RFID Shelf including the same | |
US20030197653A1 (en) | RFID antenna apparatus and system | |
US9509062B2 (en) | Alford loop antennas with parasitic elements | |
US8669904B2 (en) | Near-field antenna | |
WO2005081362A1 (en) | Antenna and rf tag | |
US20100156737A1 (en) | Broadband U-shaped RFID tag antenna with near-isotropic characteristics | |
US7786943B2 (en) | Antenna device and radio communication system | |
EP2833475B1 (en) | Dipole antenna | |
US8632009B2 (en) | Near field magnetic coupling antenna and RFID reader having the same | |
KR20100070114A (en) | Item management system using near-field rfid | |
US20120268251A1 (en) | Wireless identification tag having circularly polarized planar antenna | |
Choi et al. | Near-field antenna for RFID smart shelf in UHF | |
KR101029722B1 (en) | Spiral antenna for near field rfid application | |
KR100724491B1 (en) | Broad-Band Antenna Having Isotropy Radiation Pattern | |
KR100984109B1 (en) | Built-in RFID reader antenna used in mobile communication terminal | |
KR20100039168A (en) | U-shaped broadband rfid tag antenna with a parasitic element | |
GB2505551A (en) | Electronic shelf label (ESL) with a patch antenna embedded in its case | |
US20230019696A1 (en) | Rfid assembly | |
CN102263324A (en) | Radio frequency identification (RFID) tag antenna | |
US11705617B2 (en) | Pad structures for antennas that allow multiple orientations with RFID straps |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: ELECTRONICS AND TELECOMMUNICATIONS RESEARCH INSTIT Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:CHOI, WON KYU;JUNG, JAE-YOUNG;JEONG, SEUNG-HWAN;AND OTHERS;SIGNING DATES FROM 20121105 TO 20121107;REEL/FRAME:029669/0646 |
|
FEPP | Fee payment procedure |
Free format text: PAYOR NUMBER ASSIGNED (ORIGINAL EVENT CODE: ASPN); ENTITY STATUS OF PATENT OWNER: SMALL ENTITY |
|
STCF | Information on status: patent grant |
Free format text: PATENTED CASE |
|
FEPP | Fee payment procedure |
Free format text: MAINTENANCE FEE REMINDER MAILED (ORIGINAL EVENT CODE: REM.); ENTITY STATUS OF PATENT OWNER: SMALL ENTITY |
|
LAPS | Lapse for failure to pay maintenance fees |
Free format text: PATENT EXPIRED FOR FAILURE TO PAY MAINTENANCE FEES (ORIGINAL EVENT CODE: EXP.); ENTITY STATUS OF PATENT OWNER: SMALL ENTITY |
|
STCH | Information on status: patent discontinuation |
Free format text: PATENT EXPIRED DUE TO NONPAYMENT OF MAINTENANCE FEES UNDER 37 CFR 1.362 |
|
FP | Lapsed due to failure to pay maintenance fee |
Effective date: 20190519 |